倾斜入射时薄膜窄带滤光片的s和p偏振光的带宽会随着入射角度的增大出现分离,限制了滤光片的调谐范围。分析了偏振光带宽分离现象出现的原因和其与滤光片镜层膜系结构的关系,并得到了消除偏振光带宽分离现象的方法。根据该方法对前期设计的100GHz密集波分复用(DWDM)系统四腔角度调谐窄带滤光片进行了改进,结果表明,该方法能有效的解决偏振光带宽的分离问题,扩大调谐范围。 The bandwidth of the s and p polarized light of the narrow-band filter narrows as the angle of incidence decays as the angle of incidence increases, limiting the tuning range of the filter. The reasons for the phenomenon of polarization band separation and the relationship between them and the structure of the filter mirror layer were analyzed. The method of eliminating the polarization bandwidth separation was obtained. According to this method, the tunable Narrow-band tunable narrow-band filter in the 100GHz Dense Wavelength Division Multiplexing (DWDM) system has been improved. The results show that this method can effectively solve the problem of polarization bandwidth separation and enlarge the tuning range.